Device, system and method of simultaneously communicating with a group of wireless communication devices

ABSTRACT

Some demonstrative embodiments include devices, systems and/or methods of simultaneously communicating with a group of wireless communication devices. For example, a device may include a wireless communication unit to communicate with at least one group of a plurality of wireless communication devices over a wireless communication medium, wherein the wireless communication unit is to reserve the wireless communication medium for a time period, during which the wireless communication unit is to simultaneously transmit two or more different wireless communication transmissions to two or more wireless communication devices of the group, respectively. Other embodiments are described and claimed.

BACKGROUND

A Spatial Division Multiple Access (SDMA) communication scheme may beimplemented for communicating between a wireless communication deviceand a plurality of other wireless communication devices. The wirelesscommunication device may transmit a downlink SDMA transmission bytransmitting different signals substantially simultaneously via acombination of antennas. The combined transmitted signals may result indifferent signals, which are to be received by the plurality of otherwireless communication devices, being transmitted substantially indifferent directions on the same frequency.

The wireless communication device may receive an uplink SDMAtransmission including different signals from the plurality of otherwireless communication devices.

BRIEF DESCRIPTION OF THE DRAWINGS

For simplicity and clarity of illustration, elements shown in thefigures have not necessarily been drawn to scale. For example, thedimensions of some of the elements may be exaggerated relative to otherelements for clarity of presentation. Furthermore, reference numeralsmay be repeated among the figures to indicate corresponding or analogouselements. The figures are listed below.

FIG. 1 is a schematic block diagram illustration of a system inaccordance with some demonstrative embodiments.

FIG. 2 is a schematic illustration of a sequence of transmissionsbetween a wireless communication device and a group of other wirelesscommunication devices, in accordance with some demonstrativeembodiments.

FIG. 3 is a schematic illustration of another sequence of transmissionsbetween a wireless communication device and a group of other wirelesscommunication devices, in accordance with some demonstrativeembodiments.

FIG. 4 is a schematic flow-chart illustration of a method ofsimultaneously communicating with a group of wireless communicationdevices, in accordance with some demonstrative embodiments.

FIG. 5 is a schematic illustration of an article of manufacture, inaccordance with some demonstrative embodiments.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of some embodiments.However, it will be understood by persons of ordinary skill in the artthat some embodiments may be practiced without these specific details.In other instances, well-known methods, procedures, components, unitsand/or circuits have not been described in detail so as not to obscurethe discussion.

Discussions herein utilizing terms such as, for example, “processing”,“computing”, “calculating”, “determining”, “establishing”, “analyzing”,“checking”, or the like, may refer to operation(s) and/or process(es) ofa computer, a computing platform, a computing system, or otherelectronic computing device, that manipulate and/or transform datarepresented as physical (e.g., electronic) quantities within thecomputer's registers and/or memories into other data similarlyrepresented as physical quantities within the computer's registersand/or memories or other information storage medium that may storeinstructions to perform operations and/or processes.

The terms “plurality” and “a plurality” as used herein include, forexample, “multiple” or “two or more”. For example, “a plurality ofitems” includes two or more items.

Some embodiments may be used in conjunction with various devices andsystems, for example, a Personal Computer (PC), a desktop computer, amobile computer, a laptop computer, a notebook computer, a tabletcomputer, a server computer, a handheld computer, a handheld device, aPersonal Digital Assistant (PDA) device, a handheld PDA device, anon-board device, an off-board device, a hybrid device, a vehiculardevice, a non-vehicular device, a mobile or portable device, a consumerdevice, a non-mobile or non-portable device, a wireless communicationstation, a wireless communication device, a wireless Access Point (AP),a wired or wireless router, a wired or wireless modem, a video device,an audio device, an audio-video (A/V) device, a Set-Top-Box (STB), aBlu-ray disc (BD) player, a BD recorder, a Digital Video Disc (DVD)player, a High Definition (HD) DVD player, a DVD recorder, a HD DVDrecorder, a Personal Video Recorder (PVR), a broadcast HD receiver, avideo source, an audio source, a video sink, an audio sink, a stereotuner, a broadcast radio receiver, a flat panel display, a PersonalMedia Player (PMP), a digital video camera (DVC), a digital audioplayer, a speaker, an audio receiver, an audio amplifier, a gamingdevice, a data source, a data sink, a Digital Still camera (DSC), awired or wireless network, a wireless area network, a Wireless VideoArea Network (WVAN), a Local Area Network (LAN), a Wireless LAN (WLAN),a Personal Area Network (PAN), a Wireless PAN (WPAN), devices and/ornetworks operating in accordance with existing IEEE 802.11 (IEEE802.11-1999: Wireless LAN Medium Access Control (MAC) and Physical Layer(PHY) Specifications), 802.11a, 802.11b, 802.11g, 802.11h, 802.11j,802.11n, 802.11 task group ad (TGad), 802.16, 802.16d, 802.16e, 802.16f,standards and/or future versions and/or derivatives thereof, devicesand/or networks operating in accordance with existingWireless-Gigabit-Alliance (WGA) and/or WirelessHD™ specifications and/orfuture versions and/or derivatives thereof, units and/or devices whichare part of the above networks, one way and/or two-way radiocommunication systems, cellular radio-telephone communication systems, acellular telephone, a wireless telephone, a Personal CommunicationSystems (PCS) device, a PDA device which incorporates a wirelesscommunication device, a mobile or portable Global Positioning System(GPS) device, a device which incorporates a GPS receiver or transceiveror chip, a device which incorporates an RFID element or chip, a MultipleInput Multiple Output (MIMO) transceiver or device, a Single InputMultiple Output (SIMO) transceiver or device, a Multiple Input SingleOutput (MISO) transceiver or device, a device having one or moreinternal antennas and/or external antennas, Digital Video Broadcast(DVB) devices or systems, multi-standard radio devices or systems, awired or wireless handheld device (e.g., BlackBerry, Palm Treo), aWireless Application Protocol (WAP) device, or the like.

Some embodiments may be used in conjunction with one or more types ofwireless communication signals and/or systems, for example, RadioFrequency (RF), Infra Red (IR), Frequency-Division Multiplexing (FDM),Orthogonal FDM (OFDM), Time-Division Multiplexing (TDM), Time-DivisionMultiple Access (TDMA), Extended TDMA (E-TDMA), General Packet RadioService (GPRS), extended GPRS, Code-Division Multiple Access (CDMA),Wideband CDMA (WCDMA), CDMA 2000, single-carrier CDMA, multi-carrierCDMA, Multi-Carrier Modulation (MDM), Discrete Multi-Tone (DMT),Bluetooth®, Global Positioning System (GPS), Wi-Fi, Wi-Max, ZigBee™,Ultra-Wideband (UWB), Global System for Mobile communication (GSM), 2G,2.5G, 3G, 3.5G, Enhanced Data rates for GSM Evolution (EDGE), or thelike. Other embodiments may be used in various other devices, systemsand/or networks.

The term “wireless device” as used herein includes, for example, adevice capable of wireless communication, a communication device capableof wireless communication, a communication station capable of wirelesscommunication, a portable or non-portable device capable of wirelesscommunication, or the like. In some demonstrative embodiments, awireless device may be or may include a peripheral that is integratedwith a computer, or a peripheral that is attached to a computer. In somedemonstrative embodiments, the term “wireless device” may optionallyinclude a wireless service.

The term “substantially simultaneously”, as used herein with referenceto transmitting to two or more different wireless communication devicesand/or receiving from two or more wireless communication devices, mayrefer to transmitting and/or receiving two or more transmissions,wherein at least a portion of each transmission and/or reception occursat the same time, but does not imply that the different transmissionsand/or receptions must start and/or end at the same time, although theymay.

Some demonstrative embodiments may be used in conjunction with suitablelimited-range or short-range wireless communication networks, forexample, a wireless area network, a “piconet”, a WPAN, a WVAN and thelike. Other embodiments may be used in conjunction with any othersuitable wireless communication network.

Some demonstrative embodiments may be used in conjunction with awireless communication network communicating over a frequency band of 60GHz. However, other embodiments may be implemented utilizing any othersuitable wireless communication frequency bands, for example, anExtremely High Frequency (EHF) band (the millimeter wave (mmwave)frequency band), e.g., a frequency band within the frequency band ofbetween 30 Ghz and 300 GHZ, a WLAN frequency band, a WPAN frequencyband, a frequency band according to the IEEE 802.11, IEEE 802.11TGadand/or WGA specifications, and the like.

Reference is now made to FIG. 1, which schematically illustrates a blockdiagram of a system 100 in accordance with some demonstrativeembodiments.

As shown in FIG. 1, in some demonstrative embodiments, system 100 mayinclude a wireless communication network including one or more wirelesscommunication devices, e.g., wireless communication devices 102, 104,106, 107 and/or 108, capable of communicating content, data, informationand/or signals over a wireless communication medium 110, for example,over one or more suitable wireless communication links, e.g., a radiochannel, an IR channel, a RF channel, a Wireless Fidelity (WiFi)channel, and the like. One or more elements of system 100 may optionallybe capable of communicating over any suitable wired communication links.

In some demonstrative embodiments, wireless communication devices 102,104, 106, 107 and/or 108 may include, for example, a PC, a desktopcomputer, a mobile computer, a laptop computer, a notebook computer, atablet computer, a server computer, a handheld computer, a handhelddevice, a PDA device, a handheld PDA device, an on-board device, anoff-board device, a hybrid device (e.g., combining cellular phonefunctionalities with PDA device functionalities), a consumer device, avehicular device, a non-vehicular device, a mobile or portable device, anon-mobile or non-portable device, a cellular telephone, a PCS device, aPDA device which incorporates a wireless communication device, a mobileor portable GPS device, a DVB device, a relatively small computingdevice, a non-desktop computer, a “Carry Small Live Large” (CSLL)device, an Ultra Mobile Device (UMD), an Ultra Mobile PC (UMPC), aMobile Internet Device (MID), an “Origami” device or computing device, adevice that supports Dynamically Composable Computing (DCC), acontext-aware device, a video device, an audio device, an A/V device, aSTB, a BD player, a BD recorder, a DVD player, a HD DVD player, a DVDrecorder, a HD DVD recorder, a PVR, a broadcast HD receiver, a videosource, an audio source, a video sink, an audio sink, a stereo tuner, abroadcast radio receiver, a flat panel display, a PMP, a DVC, a digitalaudio player, a speaker, an audio receiver, a gaming device, an audioamplifier, a data source, a data sink, a DSC, a media player, aSmartphone, a television, a music player, or the like.

In some demonstrative embodiments, wireless communication device 102 mayinclude a wireless communication unit 112 to perform wirelesscommunication with wireless communication devices 104, 106, 107 and/or108 with one or more other wireless communication devices, e.g., asdescribed below. Wireless communication device 102 may also include, forexample, one or more of a processor 114, an input unit 116, an outputunit 118, a memory unit 120, and a storage unit 122. Wirelesscommunication device 102 may optionally include other suitable hardwarecomponents and/or software components. In some demonstrativeembodiments, some or all of the components of wireless communicationdevice 102 may be enclosed in a common housing or packaging, and may beinterconnected or operably associated using one or more wired orwireless links. In other embodiments, components of wirelesscommunication device 102 may be distributed among multiple or separatedevices.

Processor 114 includes, for example, a Central Processing Unit (CPU), aDigital Signal Processor (DSP), one or more processor cores, asingle-core processor, a dual-core processor, a multiple-core processor,a microprocessor, a host processor, a controller, a plurality ofprocessors or controllers, a chip, a microchip, one or more circuits,circuitry, a logic unit, an Integrated Circuit (IC), anApplication-Specific IC (ASIC), or any other suitable multi-purpose orspecific processor or controller. Processor 114 executes instructions,for example, of an Operating System (OS) of wireless communicationdevice 102 and/or of one or more suitable applications.

Input unit 116 includes, for example, a keyboard, a keypad, a mouse, atouch-pad, a track-ball, a stylus, a microphone, or other suitablepointing device or input device. Output unit 118 includes, for example,a monitor, a screen, a flat panel display, a Cathode Ray Tube (CRT)display unit, a Liquid Crystal Display (LCD) display unit, a plasmadisplay unit, one or more audio speakers or earphones, or other suitableoutput devices.

Memory unit 120 includes, for example, a Random Access Memory (RAM), aRead Only Memory (ROM), a Dynamic RAM (DRAM), a Synchronous DRAM(SD-RAM), a flash memory, a volatile memory, a non-volatile memory, acache memory, a buffer, a short term memory unit, a long term memoryunit, or other suitable memory units. Storage unit 122 includes, forexample, a hard disk drive, a floppy disk drive, a Compact Disk (CD)drive, a CD-ROM drive, a DVD drive, or other suitable removable ornon-removable storage units. Memory unit 120 and/or storage unit 122,for example, may store data processed by wireless communication device102.

In some demonstrative embodiments, wireless communication unit 112includes, for example, one or more wireless transmitters, receiversand/or transceivers able to send and/or receive wireless communicationsignals, RF signals, frames, blocks, transmission streams, packets,messages, data items, and/or data. For example, wireless communicationunit 112 may include or may be implemented as part of a wireless NetworkInterface Card (NIC), and the like.

Wireless communication unit 112 may include, or may be associated with,one or more antennas 124. Antennas 124 may include, for example, aninternal and/or external RF antenna, a dipole antenna, a monopoleantenna, an omni-directional antenna, an end fed antenna, a circularlypolarized antenna, a micro-strip antenna, a diversity antenna, or othertype of antenna suitable for transmitting and/or receiving wirelesscommunication signals, blocks, frames, transmission streams, packets,messages and/or data.

In some demonstrative embodiments, the wireless communication devices ofsystem 100 may communicate over wireless communication medium 110according to any suitable access scheme, for example, a suitablecontention-based access scheme, e.g., a random-access scheme. Forexample, system 100 may include a wireless network, e.g., a wirelessLocal-Area-Network (LAN) communicating over unlicensed frequency bands,which may operate according to a random access scheme, e.g., in order toallow coexistence with one or more other networks without requiringcentral coordination. The contention-based scheme may include, forexample, any suitable Carrier-Sense-Multiple-Access (CSMA) scheme, forexample, any suitable CSMA-with-Collision-Avoidance (CSMA/CA) scheme,e.g., according to the IEEE 802.11 standards and/or any other suitablestandard.

In some demonstrative embodiments, at least one wireless communicationdevice of system 100, e.g., wireless communication device 102, mayperform the functionality of an Access Point (AP), Control Point (CP),Base Station (BS) or any suitable coordinator or controller, e.g., asdefined by the IEEE 802.11 and/or WGA specifications.

In some demonstrative embodiments, wireless communication unit 112 maybe capable of simultaneously transmitting transmissions to two or moreother devices of system 100 and/or simultaneously receivingtransmissions from two or more other devices of system 100.

In some embodiments, wireless communication unit 112 may be capable ofperforming Spatial Division Multiple Access (SDMA) communication. Forexample, wireless communication unit 112 may transmit a downlink SDMAtransmission by transmitting different signals substantiallysimultaneously via antennas 124, such that the combined transmittedsignals result in different signals, which are intended to be receivedby two or more other wireless communication devices of system 100, beingtransmitted substantially in different directions on the same frequency.

In some demonstrative embodiments, wireless communication unit 112 mayreceive an uplink SDMA transmission including different signals from twoor more other devices of system 100.

In some demonstrative embodiments, wireless communication unit 112 maycommunicate over medium 110 with at least one group 130 of a pluralityof wireless communication devices of system 100, e.g., as described indetail below.

In some demonstrative embodiments, group 130 may include a plurality ofwireless communication devices, e.g., wireless communication devices104, 106 and/or 107, which may be suitable for simultaneous downlinkand/or uplink wireless communication with wireless communication unit112. For example, group 130 may include a SDMA group of devices suitablefor unidirectional, e.g., in an uplink direction to device 102 and/or adownlink direction from device 102, and/or bidirectional communicationwith wireless communication unit 112, e.g., as described below.

In some demonstrative embodiments, the wireless communication devices ofgroup 130 may be grouped together, e.g., by wireless communication unit112, according to any suitable criteria, for example, one or moretraffic-specification (TSPEC) requirements, e.g., quality of servicerequirements, bandwidth requirements, traffic pattern requirements, andthe like, and/or any other suitable requirement and/or parameter.

In some demonstrative embodiments, wireless communication unit 112 maybe capable of receiving the TSPEC information corresponding to wirelesscommunication devices 104, 106 and/or 107 as a part of an Add TrafficStream (ADDTS) Request frame. The ADDTS frame received from a wirelesscommunication device may include a suitable TSPEC Information Element(IE) and/or field, which may include the TSPEC information correspondingto the wireless communication device. In other embodiments, wirelesscommunication unit 112 may receive the TSPEC information as part of anyother suitable frame and/or communication and/or in any other suitableformat.

In some demonstrative embodiments, the TSPEC information correspondingto a wireless communication device, as received by wirelesscommunication unit 112, may include traffic flow information defining atraffic flow between the wireless communication device and wirelesscommunication unit 112. The TSPEC information corresponding to thewireless communication device may include, for example, one or more of atraffic pattern of the traffic flow, a Quality of Service (QoS) of thetraffic flow, and/or any other series of requirements, parameters,characteristics and/or expectations of a traffic flow. For example,wireless communication unit 112 may receive a first ADDTS frame fromwireless communication device 104, including traffic flow information,e.g., a traffic pattern and/or a QoS, defining a traffic flow betweenwireless communication device 104 and wireless communication unit 112; asecond ADDTS frame from wireless communication device 106, includingtraffic flow information, e.g., a traffic pattern and/or a QoS, defininga traffic flow between wireless communication device 106 and wirelesscommunication unit 112; and/or a third ADDTS frame from wirelesscommunication device 107, including traffic flow information, e.g., atraffic pattern and/or a QoS, defining a traffic flow between wirelesscommunication device 107 and wireless communication unit 112.

In some demonstrative embodiments, the TSPEC information, received bywireless communication unit 112 from a wireless communication device,may include a directionality of the traffic flow between the wirelesscommunication device and wireless communication unit 112. Thedirectionality of the traffic flow may be determined, for example, basedon the traffic pattern of the traffic flow. For example, thedirectionality of the traffic flow may include an uplink traffic flow,e.g., including uplink transmissions from the wireless communicationdevice to wireless communication unit 112; a downlink traffic flow,e.g., including downlink transmissions from wireless communication unit112 to the wireless communication device; or a bidirectional trafficflow, e.g., including both uplink transmissions and downlinktransmissions.

In some demonstrative embodiments, the QoS of the traffic flow mayinclude, for example, a QoS parameter representing, for example, apriority type of the traffic flow, e.g., guaranteeing a certain level ofperformance. The priority type of the traffic flow may be selected, forexample, from a set of predefined priority types. In one example, theQoS of the traffic flow may be selected from a set of four predefinedpriority types, for example, a video priority type, an audio (voice)priority type, a best effort priority type, and a background prioritytype, e.g., as defined by the 802.11 standard and/or any other suitablestandard.

In some demonstrative embodiments, the traffic flow corresponding to awireless communication device may be categorized as an isochronoustraffic flow, for example, if the traffic flow includes a time-dependenttraffic flow, e.g., including video and/or voice data; and/or as anasynchronous traffic flow, for example, if the traffic flow is nottime-dependent, e.g., if the traffic flow does not include video orvoice data.

In some demonstrative embodiments, wireless communication unit 112 mayassign wireless communication devices 104, 106 and/or 107 to one or moregroups, e.g., including group 130, based on the categorization and/ordirectionality of the traffic flows corresponding to wirelesscommunication devices 104, 106 and/or 107.

In some demonstrative embodiments, wireless communication unit 112 mayassign wireless communication devices 104, 106 and/or 107 to an uplinkisochronous group, a downlink isochronous group, a bidirectionalisochronous group, and/or a bi-directional asynchronous group. In otherembodiments, wireless communication unit 112 may assign wirelesscommunication devices 104, 106 and/or 107 to any other suitable group.

In some demonstrative embodiments, wireless communication unit 112 mayassign a wireless communication device of devices 104, 106 and 107 tothe uplink isochronous group, for example, if the TSPEC informationcorresponding to the wireless communication device represents an uplinktraffic pattern including at least one of video and voice data; wirelesscommunication unit 112 may assign the wireless communication device tothe downlink isochronous group if the TSPEC information corresponding tothe wireless communication device represents a downlink traffic patternincluding at least one of video and voice data; wireless communicationunit 112 may assign the wireless communication device to thebi-directional isochronous group if the TSPEC information correspondingto the wireless communication device represents a bidirectional trafficpattern including at least one of video and voice data; and/or wirelesscommunication unit 112 may assign the wireless communication device tothe bi-directional asynchronous group if the TSPEC informationcorresponding to the wireless communication device represents anothertraffic pattern.

Although some embodiments are described herein with reference toassigning a wireless communication device to a group based on the TSPECinformation corresponding to the wireless communication device, otherembodiments may include one or more wireless communication devicesassigned to a group based on any other suitable criteria.

In some demonstrative embodiments, wireless communication unit 112 mayassign wireless communication devices 104, 106 and 107 to group 130, andprovide to wireless communication devices 104, 106 and/or 107 suitablegroup allocation information defining group 130 and/or relating to group130.

In some demonstrative embodiments, wireless communication unit 112 mayassign to group 130 a wireless communication address (also referred toas “group address” or “multicast address”). The group address assignedto group 130 may include, for example, a suitable Media-Access-Control(MAC) address, which may be assigned uniquely, e.g., within system 100and/or a Basic-Service-Set (BSS) controlled and/or managed by wirelesscommunication unit 112.

In some demonstrative embodiments, wireless communication unit 112 mayinform wireless communication devices 104, 106 and/or 107 of the groupaddress assigned to group 130, for example, using any suitabletransmission, frame and/or packet. For example, wireless communicationunit 112 may transmit one or more unicast frames to wirelesscommunication devices 104, 106 and/or 107, e.g., a first groupallocation frame addressed to wireless communication device 104, asecond group allocation frame addressed to wireless communication device106 and/or a third group allocation frame addressed to wirelesscommunication device 107. The first, second and third group allocationframes may include, for example, the group address of group 130.

In some demonstrative embodiments, wireless communication unit 112 maydetermine, e.g., based on any suitable criteria, an order at whichwireless communication devices 104, 106 and/or 107 are to respond to atransmission from wireless communication unit 112, for example, suchthat wireless communication devices 104, 106 and 107 may respond duringnon-overlapping time periods, e.g., as described below. For example,wireless communication unit 112 may determine that wirelesscommunication device 106 is to respond to the transmission from wirelesscommunication unit 112 a first offset time after the transmission fromwireless communication unit 112, that wireless communication device 104is to respond to the transmission from wireless communication unit 112 asecond offset time, which is longer than the first offset time after thetransmission, and/or that wireless communication device 107 is torespond to the transmission from wireless communication unit 112 a thirdoffset time, which is longer than the second offset time after thetransmission. A difference between the second and first offset timesand/or difference between the third and second offset times may be atleast equal to a duration of the responses from wireless communicationdevices 104 and/or 106, e.g., to allow wireless communication devices104, 106 and 107 to respond during non-overlapping periods.

In some demonstrative embodiments, wireless communication unit 112 mayinclude an indication of the required order, e.g., in the groupallocation frame. For example, the group allocation frame may includevalues, for example in the form of suitable Association Identifiers(AIDs) and/or suitable MAC addresses, representing wirelesscommunication devices 104, 106 and 107 according to the required order.For example, the group allocation frame may include a value representingthe MAC address of wireless communication device 106 followed by a valuerepresenting the MAC address of wireless communication device 104, whichin turn may be followed by a value representing the MAC address ofwireless communication device 107, e.g., if wireless communicationdevice 106 is to respond to wireless communication unit 112 prior to aresponse from wireless communication device 104, which in turn is torespond to wireless communication unit 112 prior to a response fromwireless communication device 107.

In some demonstrative embodiments, wireless communication devices 104,106 and/or 107 may each determine the order at which to respond towireless communication unit 112, based on the indication of the requiredorder.

In some embodiments, wireless communication devices 104, 106 and/or 107may transmit the responses at a data rate equal to a data rate of thetransmission from wireless communication unit 112, e.g., in order toallow wireless communication devices 104, 106 and/or 107 to schedule thetransmission of the responses, such that wireless communication device112 may be able to receive the responses.

In another embodiment, wireless communication units 104, 106 and/or 107may transmit the responses at a selected predefined data rate forcommunication with wireless communication unit 112. In one example,wireless communication units 104, 106 and/or 107 may transmit theresponses at a data rate, which is selected from a predefined set ofdata rates implemented for communication in system 100, e.g., theBSSBasicRateSet as defined by the 802.11 standards. For example,wireless communication units 104, 106 and/or 107 may transmit theresponses at a highest data rate of the BSSBasicRateSet, which is lessthan or equal to a rate of an immediately previous frame received fromwireless communication unit 112.

In some demonstrative embodiments, wireless communication unit 112 mayassign wireless communication devices 104, 106 and/or 107 to group 130,for example, while not directly providing wireless communication units104, 106 and/or 107 with information defining group 130 and/or relatingto group 130. According to this example, wireless communication unit 112may simultaneously transmit downlink transmissions to devices of group130, e.g., while one or more of the wireless communication devices ofgroup 130 may not be aware of the simultaneous transmission to otherdevices in group 130, for example, if the one or more wirelesscommunication devices are not required to and/or is not able to transmituplink SDMA transmissions to wireless communication unit 112. Forexample, wireless communication unit 112 may transmit a downlink SDMAtransmission to a wireless communication device, e.g., device 107, whilethe wireless communication device may not be aware of the fact that thedownlink transmission is a downlink SDMA transmission, for example, ifwireless communication device 107 is not required to and/or is not ableto transmit uplink SDMA transmissions to wireless communication unit112.

In some demonstrative embodiments, wireless communication unit 112 mayreserve wireless communication medium 110 for a time period, duringwhich wireless communication unit 112 is to simultaneously transmit twoor more different wireless communication transmissions to two or morewireless communication devices of group 130, respectively, e.g., asdescribed in detail below.

Reference is also made to FIG. 2, which schematically illustrates asequence of transmissions between a wireless communication device, e.g.,wireless communication device 102 (FIG. 1) and/or wireless communicationunit 112 (FIG. 1), and a group of other wireless communication devices,e.g., group 130 (FIG. 1), in accordance with some demonstrativeembodiments.

As shown in FIG. 2, a timeline 202 includes transmissions by thewireless communication device, e.g., wireless communication unit 112(FIG. 1); a timeline 204 includes transmissions by a first wirelesscommunication device of the group, e.g., wireless communication device104 (FIG. 1); a timeline 206 includes transmissions by a second wirelesscommunication device of the group, e.g., wireless communication device106 (FIG. 1); and a timeline 208 includes transmissions by a thirdwireless communication device of the group, e.g., wireless communicationdevice 107 (FIG. 1).

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may reserve wireless communication medium 110 (FIG. 1) for atleast a time period 215, during which wireless communication unit 112(FIG. 1) is to simultaneously transmit two or more different wirelesscommunication transmissions 214 to two or more wireless communicationdevices of group 130, respectively.

In some demonstrative embodiments, transmissions 214 may be transmittedas part of a SDMA transmission including three, e.g., different, datapackets, denoted data1, data2, and data3, e.g., three aggregate MACprotocol data unit (AMPDUs), to be received by wireless communicationdevices 104, 106 and/or 107, respectively. In one example, the threedata packets data1, data2, and data3 may include data packets ofdifferent lengths. According to this example, the reserved duration 215may correspond to at least the length of the longest data packet.

In some demonstrative embodiments, reserved time period 215 may includeat least the transmission duration of transmissions 214 and/or any oneor more uplink and/or downlink transmissions associated withtransmissions 214, for example, one or more uplink and/or downlinktransmissions to confirm and/or acknowledge receipt of transmissions214, e.g., as described below.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may reserve medium 110 (FIG. 1) according to a firstreservation scheme 212 by transmitting at least one Request-To-Send(RTS) packet 219 to one or more wireless communication devices of group130 (FIG. 1). The RTS packet 219 may include a duration valuecorresponding to the time period to be reserved 215. For example, aduration filed of RTS packet 219 may be set by wireless communicationunit 112 (FIG. 1) to include a value corresponding to the time period tobe reserved 215.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may transmit RTS packet 219 addressed to the wirelesscommunication devices of group 130 (FIG. 1). For example, wirelesscommunication unit 112 (FIG. 1) may transmit RTS packet 219 includingthe group address assigned to group 130, for example, after informingwireless communication devices 104, 106 and/or 107 of the group address,e.g., as described above.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may receive one or more clear-to-send (CTS) packets from one ormore wireless communication devices of group 130 (FIG. 1), e.g., inresponse to RTS packet 219. For example, wireless communication unit 112(FIG. 1) may receive a first CTS packet 222 from wireless communicationdevice 104 (FIG. 1) and a second CTS packet 224 from wirelesscommunication device 106 (FIG. 1). As shown in FIG. 2, in one example,wireless communication unit 112 (FIG. 1) may not receive a CTS packetfrom one or more devices of group 130 (FIG. 1), e.g., from wirelesscommunication device 107 (FIG. 1), e.g., due to a collision,interference and/or any other reason.

As shown in FIG. 2, in some demonstrative embodiments CTS packets 222and 224 may be transmitted by wireless communication devices 104 and 106(FIG. 1) substantially simultaneously and/or CTS packets 222 and 224 maybe received substantially simultaneously by wireless communication unit112 (FIG. 1), for example, if wireless communication devices 104 and/or106 support uplink SDMA transmissions.

In some demonstrative embodiments, CTS packets 222 and 224 may beidentical to one another. For example, both wireless communicationdevices 104 and 106 may generate CTS packets 222 and 224, respectively,using a common scrambling seed, e.g., the scrambling seed of RTS packet219.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may receive and decode CTS packets 222 and 224. A wirelesscommunication device of system 100 (FIG. 1) not belonging to group 130(FIG. 1), e.g., wireless communication device 108 (FIG. 1), may receiveCTS packets 222 and/or 224. Since CTS packets 222 and 224 may beidentical to one another, the wireless communication device may decodeCTS packets 222 and 224, e.g., assuming packets 222 and 224 haveresulted from a multi-path effect.

In some demonstrative embodiments, another wireless communication deviceof system 100 (FIG. 1) receiving CTS packets 222 and/or 224, forexample, a wireless communication device of group 130 (FIG. 1), e.g.,wireless communication device 107, and/or a wireless communicationdevice not included in group 130 (FIG. 1), e.g., wireless communicationdevice 108 (FIG. 1), may avoid performing transmissions over wirelesscommunication medium 110 (FIG. 1) during reserved time period 215.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may simultaneously transmit transmissions 214 to two or morewireless communication devices (“the two or more addressed devices”) ofgroup 130. The two or more addressed devices may include two or morewireless communication devices of group 130 (FIG. 1) from which wirelesscommunication unit 112 (FIG. 1) has received two or more CTS packets,respectively. For example, if wireless communication unit 112 (FIG. 1)receives CTS packets 222 and 224, then wireless communication unit 112(FIG. 1) may transmit transmission 214 including the data packets data1and data2 intended for wireless communication devices 104 and 106 (FIG.1), respectively, e.g., while not including the data packet data3intended for wireless communication device 107 (FIG. 1), from which aCTS packet has not been received by wireless communication unit 112(FIG. 1).

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may reserve medium 110 (FIG. 1) according to a secondreservation scheme 210 by transmitting a data packet 218, including aduration value corresponding to the time period to be reserved 215, toat least one of the wireless communication devices of group 130, e.g.,to wireless communication device 107 (FIG. 1). For example, a durationfiled of data packet 218 may be set by wireless communication unit 112(FIG. 1) to include a value corresponding to the time period to bereserved 215. Wireless communication device 107 (FIG. 1) may respondwith a suitable acknowledgment (ACK) packet 220. As a result, anotherwireless communication device of system 100 (FIG. 1) receiving datapacket 218 and/or ACK 220, for example, a wireless communication deviceof group 130 (FIG. 1), e.g., wireless communication devices 104 and/or106, and/or a wireless communication device not included in group 130(FIG. 1), e.g., wireless communication device 108 (FIG. 1), may avoidperforming transmissions over wireless communication medium 110 (FIG. 1)during reserved time period 215.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may simultaneously transmit transmissions 214 to the two ormore addressed wireless communication devices of group 130 (FIG. 1). Forexample, wireless communication unit 112 (FIG. 1) may transmittransmission 214 including the simultaneous transmission of data packetsdata1, data2 and data3 to wireless communication devices 104, 106 and107 (FIG. 1), respectively.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may transmit at least one block-acknowledgement-request (BAR)216 to the two or more addressed devices. In one embodiment, wirelesscommunication unit 112 (FIG. 1) may simultaneously transmit BAR 216 aspart of a downlink SDMA transmission to the two or more addresseddevices. In other embodiments, wireless communication unit 112 (FIG. 1)may transmit BAR 216 as part of two or more separate unicasttransmissions to the two or more addressed devices, respectively.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may receive from the two or more addressed devices two or morerespective block-acknowledgments (BAs). For example, wirelesscommunication unit 112 (FIG. 1) may transmit BAR 216 as part of adownlink SDMA transmission to wireless communication devices 104, 106and/or 107 (FIG. 1) and, in response, wireless communication unit 112(FIG. 1) may receive BA 232 from wireless communication unit 104 (FIG.1), BA 234 from wireless communication unit 106 (FIG. 1) and/or BA 236from wireless communication unit 107 (FIG. 1).

As shown in FIG. 2, wireless communication devices 104, 106 and/or 107(FIG. 1) may be capable of performing uplink SDMA transmissions. Forexample, as shown in FIG. 2, CTS packets 222 and 224 may be transmittedby wireless communication devices 104 and 106 (FIG. 1) substantiallysimultaneously; CTS packets 222 and 224 may be received substantiallysimultaneously by wireless communication unit 112 (FIG. 1); BA 232, BA234 and 236 may be transmitted by wireless communication devices 104,106 and 107 (FIG. 1), respectively, substantially simultaneously; and/orBA 232 and 234 may be received by wireless communication unit 112(FIG. 1) substantially simultaneously. However, in other embodiments,uplink transmissions from wireless communication devices 104, 106 and/or107 (FIG. 1) may be performed sequentially, e.g., as described below.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may determine the order (“the response order”) at whichwireless communication devices 104, 106 and/or 107 (FIG. 1) are torespond to transmissions from wireless communication unit 112 (FIG. 1),for example, if wireless communication devices 104, 106 and/or 107(FIG. 1) do not support SDMA uplink transmissions. Wirelesscommunication unit 112 (FIG. 1) may inform wireless communicationdevices 104, 106 and/or 107 (FIG. 1) of the response order, e.g., usingthe group allocation frame, as described above. In other embodiments,the response order at which wireless communication devices 104, 106and/or 107 (FIG. 1) are to respond to transmissions from wirelesscommunication unit 112 (FIG. 1) may be determined and/or provided towireless communication devices 104, 106 and/or 107 (FIG. 1) according toany other suitable criterion and/or scheme.

In some demonstrative embodiments, wireless communication units 104and/or 106 (FIG. 1) may transmit respective CTS packets 222 and 224sequentially and/or wireless communication units 104, 106 and/or 107(FIG. 1) may transmit respective BA packets 232, 234 and 236sequentially, e.g., according to the response order. For example,wireless communication unit 112 (FIG. 1) may allocate a first responseperiod to wireless communication device 104 (FIG. 1), and a secondresponse period, succeeding the first period, to wireless communicationdevice 106, for transmitting CTS packets 222 and 224, respectively. Forexample, the beginning of the second response period may be delayed,with respect to the beginning of the first response period, by thecombined duration of a CTS packet transmission and ashort-inter-frame-space (SIFS) period, and/or any other time period.Accordingly, wireless communication device 104 (FIG. 1) may transmit CTSpacket 222 during the first response period, and wireless communicationdevice 106 (FIG. 1) may transmit CTS packet 224 during the second timeperiod, such that the transmissions of CTS packets 222 and 224 do notoverlap. Similarly, if the response order defines wireless communicationdevice 107 (FIG. 1) is to respond after wireless communication device106 (FIG. 1), which in turn is to respond after wireless communicationunit 104 (FIG. 1), then wireless communication unit 106 (FIG. 1) maybegin the transmission of BA 234 at a BA delay, e.g., equal to thecombined duration of a BA transmission and a SIFS, after the beginningof the transmission of BA 232; and/or wireless communication unit 107(FIG. 1) may begin the transmission of BA 236 at the BA after thebeginning of the transmission of BA 234. Accordingly, wirelesscommunication devices 104, 106 and/or 107 (FIG. 1) may sequentiallytransmit BAs 232, 234 and/or 236, respectively, such that thetransmissions of BAs 232, 234 and 236 do not overlap.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may include in one or more of transmissions 214, e.g., in eachof transmissions 214, an indication of the duration of a longesttransmission of transmissions 214. For example, wireless communicationunit 112 (FIG. 1) may include in each of data packets data1, data2, anddata 3 an indication of the duration of a longest one of data packetsdata1, data2, and data 3. In one example, transmissions 214 includeAMPDUs, and wireless communication unit 112 (FIG. 1) may include anindication of the duration of the longest AMPDU in each one of theAMPDUs, e.g., in the L-SIG field. Accordingly, each of wirelesscommunication devices 104, 106 and 107 (FIG. 1) may determine whentransmissions 214 are to end. At the end of transmissions 214, wirelesscommunication devices 104, 106 and/or 107 (FIG. 1) may transmit BAs 232,234 and/or 236, respectively, e.g., without having to receive BAR 216.Wireless communication devices 104, 106 and/or 107 (FIG. 1) may transmitBAs 232, 234 and/or 236, respectively, in a simultaneous manner, e.g.,if uplink SDMA is supported, or sequentially, e.g., if uplink SDMA isnot supported, e.g., as discussed above.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may transmit RTS packet 219 in the form of an Extended RTS(ERTS) intended for only some wireless communication devices (“theselected devices”) of group 130 (FIG. 1), e.g., to which wirelesscommunication unit 112 (FIG. 1) has buffered traffic. The ERTS packetmay also indicate the response order of the selected devices.Accordingly, wireless communication unit 112 (FIG. 1) may receive CTSpackets from only the selected devices, e.g., according to the responseorder, and transmit transmissions 214 to the intended devices. Wirelesscommunication unit 112 (FIG. 1) may transmit an Extended BAR (EBAR) toschedule BA transmissions from only the selected devices.

Referring back to FIG. 1, in some demonstrative embodiments, wirelesscommunication unit 112 may determine a beamforming (BF) scheme forcommunicating with devices 104, 106 and/or 107 by performing abeamforming training sequence including an exchange of at least onesimultaneous transmission with two or more devices 104, 106 and 107. Thebeamforming training sequence may include an implicit beamformingsequence and/or an explicit beamforming sequence, e.g., as describedbelow.

Reference is also made to FIG. 3, which schematically illustratesanother sequence of transmissions between a wireless communicationdevice, e.g., wireless communication device 102 (FIG. 1) and/or wirelesscommunication unit 112 (FIG. 1), and a group of other wirelesscommunication devices, e.g., group 130 (FIG. 1), in accordance with somedemonstrative embodiments.

As shown in FIG. 3, a timeline 302 includes transmissions by thewireless communication device, e.g., wireless communication unit 112(FIG. 1); a timeline 304 includes transmissions by a first wirelesscommunication device of the group, e.g., wireless communication device104 (FIG. 1); a timeline 306 includes transmissions by a second wirelesscommunication device of the group, e.g., wireless communication device106 (FIG. 1); and a timeline 308 includes transmissions by a thirdwireless communication device of the group, e.g., wireless communicationdevice 107 (FIG. 1).

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may transmit at least one beamforming-training initiation frame310 to two or more wireless communication devices of group 130 (FIG. 1).Wireless communication unit 112 (FIG. 1) may receive two or morefeedback frames from the two or more wireless communication devices. Forexample, wireless communication unit 112 (FIG. 1) may receive feedbackframes 312, 314 and/or 316 from wireless communication devices 104, 106and/or 107 (FIG. 1), respectively.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may determine two or more beamforming schemes based on the twoor more feedback frames. For example, wireless communication unit 112(FIG. 1) may implement any suitable beamforming training and/ordetection method to determine the beamforming schemes to be used forcommunicating with wireless communication devices 104, 106 and/or 107(FIG. 1) based on feedback frames 312, 314 and/or 316, respectively.

In some demonstrative embodiments, initiation frame 310 and feedbackframes 312, 314 and/or 316 may be exchanged as part of an implicitbeamforming training sequence. For example, initiation frame 310 mayinclude a Training Request (TRQ, also referred to as a sounding request)and/or feedback frames 312, 314 and/or 316 may include suitable channelsounding frames. In one embodiment, initiation frame 310 may include anysuitable management, control and/or data frame, which may include a TRQbit set to a predefined value, e.g., one, indicating that initiationframe 310 is to be treated as a TRQ.

In some demonstrative embodiments, initiation frame 310 and feedbackframes 312, 314 and/or 316 may be exchanged as part of an explicitbeamforming training sequence. For example, initiation frame 310 mayinclude a suitable channel sounding frame and/or feedback frames 312,314 and/or 316 may include beamforming feedback frames in response tothe sounding frame.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may transmit initiation frame 310 including the group addressassigned to group 130 (FIG. 1), e.g., as described above. Initiationframe 310 may be transmitted in the form of an extended frame, e.g., anExtended TRQ (ETRQ), including the response order assigned to thewireless communication devices of group 130 (FIG. 1), e.g., as describedabove, for example, to inform wireless communication devices 104, 106and/or 107 (FIG. 1) of an order at which feedback frames 312, 314 and/or316 are to be transmitted sequentially. Wireless communication devices104, 106 and/or 107 (FIG. 1) may respond to initiation frame 310 bysending feedback frames 312, 314 and/or 316 including suitable soundingframes.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may transmit an individual initiation frame 310 to each ofwireless communication devices 104, 106 and/or 107 (FIG. 1), e.g., aspart of a unicast transmission.

In some demonstrative embodiments, wireless communication unit 112(FIG. 1) may transmit two or more different wireless communicationtransmissions 318 to the two or more wireless communication devices,respectively, using the two or more beamforming schemes, respectively.For example, wireless communication unit 112 (FIG. 1) may transmittransmissions 318 as part of a SDMA scheme, e.g., as described above. Inone example, wireless communication unit 112 (FIG. 1) may transmit a BAR320 following transmissions 318 and/or receive BAs 322, 324 and/or 326in response to BAR 320, e.g., as described above.

Reference is made to FIG. 4, which schematically illustrates a method ofsimultaneously communicating with a group of wireless communicationdevices, in accordance with some demonstrative embodiments. In someembodiments, one or more operations of the method of FIG. 4 may beperformed by system 100 (FIG. 1) and/or one or more of devices 102, 104,106, 107 and/or 108 (FIG. 1).

As indicated at block 402, the method may include reserving, by awireless communication unit, a wireless communication medium for a timeperiod. For example, wireless communication unit 112 (FIG. 1) mayreserve wireless communication medium 110 (FIG. 1), e.g., as describedabove.

As indicated at block 406, in some embodiments reserving the wirelesscommunication medium may include transmitting at least one RTS packet toone or more wireless communication devices of the group, wherein therequest-to-send packet includes a duration value corresponding to thetime period to be reserved. For example, wireless communication unit 112(FIG. 1) may transmit RTS packet 219 (FIG. 2), e.g., as described above.The RTS packet may include the group address assigned to the group ofwireless communication devices, e.g., as described above.

As indicated at block 408, the method may include transmitting thetransmissions to the two or more wireless communication devices afterreceiving two or more CTS packets from the two or more wirelesscommunication devices, in response to the request-to-send packet. Forexample, wireless communication unit 112 (FIG. 1) may transmittransmissions 214 (FIG. 2) after receiving CTS packets 222 and 224 (FIG.2), e.g., as described above. The two or more CTS packets may beidentical, e.g., as described above.

As indicated at block 410, in some embodiments reserving the wirelesscommunication medium may include transmitting a data packet to at leastone of the wireless communication devices of the group, wherein thepacket includes a duration value corresponding to the time period to bereserved. For example, wireless communication unit 112 (FIG. 1) maytransmit packet 218 (FIG. 2), e.g., as described above.

As indicated at block 404, the method may include simultaneouslytransmitting, during the reserved time period, two or more differentwireless communication transmissions from the wireless communicationunit to two or more respective wireless communication devices of a groupof a plurality of wireless communication devices. For example, wirelesscommunication unit 112 (FIG. 1) may transmit transmissions 214 (FIG. 2)to two or more wireless communication devices of group 130 (FIG. 1)during the reserved time period, e.g., as described above.

As indicated at block 412, in some embodiments the method may includedetermining a beamforming scheme for communicating with the wirelesscommunication devices of the group.

As indicated at block 414, the method may include transmitting at leastone beamforming-training initiation frame from the wirelesscommunication unit to the group of wireless communication devices. Forexample, wireless communication unit 112 (FIG. 1) may transmit frame 310(FIG. 3), e.g., as described above.

As indicated at block 416, the method may include receiving at thewireless communication unit two or more feedback frames from the two ormore wireless communication devices. For example, wireless communicationunit 112 (FIG. 1) may receive frames 312, 314 and/or 316 (FIG. 3), e.g.,as described above.

As indicated at block 418, the method may include determining two ormore beamforming schemes based on the two or more feedback frames. Forexample, wireless communication unit 112 (FIG. 1) may determine thebeamforming schemes to be used for communicating with wirelesscommunication devices 104, 106 and/or 107 (FIG. 1) based on frames 312,314 and/or 316 (FIG. 3), respectively, e.g., as described above.

As indicated at block 420, the method may include transmitting the twoor more different wireless communication transmissions to the two ormore wireless communication devices, respectively, using the two or morebeamforming schemes, respectively. For example, wireless communicationunit 112 (FIG. 1) may transmit transmissions 318 (FIG. 3) using thebeamforming schemes corresponding to wireless communication devices 104,106 and/or 107 (FIG. 1), e.g., as described above.

Reference is made to FIG. 5, which schematically illustrates an articleof manufacture 500, in accordance with some demonstrative embodiments.Article 500 may include a machine-readable storage medium 502 to storelogic 504, which may be used, for example, to perform at least part ofthe functionality of wireless communication unit 112 (FIG. 1) and/or toperform one or more operations of the method of FIG. 4.

In some demonstrative embodiments, article 500 and/or machine-readablestorage medium 502 may include one or more types of computer-readablestorage media capable of storing data, including volatile memory,non-volatile memory, removable or non-removable memory, erasable ornon-erasable memory, writeable or re-writeable memory, and the like. Forexample, machine-readable storage medium 502 may include, RAM, DRAM,Double-Data-Rate DRAM (DDR-DRAM), SDRAM, static RAM (SRAM), ROM,programmable ROM (PROM), erasable programmable ROM (EPROM), electricallyerasable programmable ROM (EEPROM), Compact Disk ROM (CD-ROM), CompactDisk Recordable (CD-R), Compact Disk Rewriteable (CD-RW), flash memory(e.g., NOR or NAND flash memory), content addressable memory (CAM),polymer memory, phase-change memory, ferroelectric memory,silicon-oxide-nitride-oxide-silicon (SONOS) memory, a disk, a floppydisk, a hard drive, an optical disk, a magnetic disk, a card, a magneticcard, an optical card, a tape, a cassette, and the like. Thecomputer-readable storage media may include any suitable media involvedwith downloading or transferring a computer program from a remotecomputer to a requesting computer carried by data signals embodied in acarrier wave or other propagation medium through a communication link,e.g., a modem, radio or network connection.

In some demonstrative embodiments, logic 504 may include instructions,data, and/or code, which, if executed by a machine, may cause themachine to perform a method, process and/or operations as describedherein. The machine may include, for example, any suitable processingplatform, computing platform, computing device, processing device,computing system, processing system, computer, processor, or the like,and may be implemented using any suitable combination of hardware,software, firmware, and the like.

In some demonstrative embodiments, logic 504 may include, or may beimplemented as, software, a software module, an application, a program,a subroutine, instructions, an instruction set, computing code, words,values, symbols, and the like. The instructions may include any suitabletype of code, such as source code, compiled code, interpreted code,executable code, static code, dynamic code, and the like. Theinstructions may be implemented according to a predefined computerlanguage, manner or syntax, for instructing a processor to perform acertain function. The instructions may be implemented using any suitablehigh-level, low-level, object-oriented, visual, compiled and/orinterpreted programming language, such as C, C++, Java, BASIC, Matlab,Pascal, Visual BASIC, assembly language, machine code, and the like.

Functions, operations, components and/or features described herein withreference to one or more embodiments, may be combined with, or may beutilized in combination with, one or more other functions, operations,components and/or features described herein with reference to one ormore other embodiments, or vice versa.

While certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents may occur to those skilled in the art. It is, therefore, tobe understood that the appended claims are intended to cover all suchmodifications and changes as fall within the true spirit of theinvention.

What is claimed is:
 1. An apparatus comprising a memory and a processorconfigured to cause an Access Point (AP) to: transmit a Request to Send(RTS) addressed to a plurality of wireless communication devices, theRTS comprising a duration value to reserve a wireless medium for areserved time period; process a plurality of simultaneous Clear to Send(CTS) responses from the plurality of wireless communication devices;and subsequent to the CTS responses, transmit a downlink transmissionaddressed to the plurality of wireless communication devices during thereserved time period.
 2. The apparatus of claim 1 configured to causethe AP to process acknowledgement responses from the plurality ofwireless communication devices subsequent to the downlink transmission.3. The apparatus of claim 2, wherein the reserved time period comprisesat least a duration of the downlink transmission and a duration of theacknowledgement responses.
 4. The apparatus of claim 1, wherein a CTSresponse of the plurality of CTS responses is based on scramblinginformation of the RTS.
 5. The apparatus of claim 1, wherein the RTScomprises an address field to address the plurality of wirelesscommunication devices.
 6. The apparatus of claim 1, wherein the downlinktransmission comprises simultaneous transmission of a plurality ofdifferent downlink data frames to respective ones of the plurality ofwireless communication devices.
 7. The apparatus of claim 1 comprising aradio to transmit the RTS, receive the CTS responses, and transmit thedownlink transmission.
 8. The apparatus of claim 1 comprising one ormore antennas.
 9. A product comprising one or more tangiblecomputer-readable non-transitory storage media comprisingcomputer-executable instructions operable to, when executed by at leastone computer processor, enable the at least one computer processor toimplement at an Access Point (AP) operations comprising: transmitting aRequest to Send (RTS) addressed to a plurality of wireless communicationdevices, the RTS comprising a duration value to reserve a wirelessmedium for a reserved time period; processing a plurality ofsimultaneous Clear to Send (CTS) responses from the plurality ofwireless communication devices; and subsequent to the CTS responses,transmitting a downlink transmission addressed to the plurality ofwireless communication devices during the reserved time period.
 10. Theproduct of claim 9, wherein the operations comprise processingacknowledgement responses from the plurality of wireless communicationdevices subsequent to the downlink transmission.
 11. The product ofclaim 10, wherein the reserved time period comprises at least a durationof the downlink transmission and a duration of the acknowledgementresponses.
 12. The product of claim 9, wherein a CTS response of theplurality of CTS responses is based on scrambling information of theRTS.
 13. The product of claim 9, wherein the RTS comprises an addressfield to address the plurality of wireless communication devices. 14.The product of claim 9, wherein the downlink transmission comprisessimultaneous transmission of a plurality of different downlink dataframes to respective ones of the plurality of wireless communicationdevices.
 15. An apparatus comprising a memory and a processor configuredto cause a wireless communication device to: process a Request to Send(RTS) from an Access Point (AP), the RTS addressed to a plurality ofwireless communication devices comprising the wireless communicationdevice, the RTS comprising a duration value to reserve a wireless mediumfor a reserved time period; transmit a Clear to Send (CTS) response tothe AP, the CTS response is based on scrambling information of the RTS;and subsequent to the CTS response, process a downlink transmission fromthe AP, the downlink transmission comprises a transmission from the APaddressed to the plurality of wireless communication devices during thereserved time period.
 16. The apparatus of claim 15 configured to causethe wireless communication device to transmit the CTS responsesimultaneously with CTS responses from other wireless communicationdevices of said plurality of wireless communication devices.
 17. Theapparatus of claim 15 configured to cause the wireless communicationdevice to transmit an acknowledgement response to the AP subsequent tothe downlink transmission.
 18. The apparatus of claim 17, wherein thereserved time period comprises at least a duration of the downlinktransmission and a duration of the acknowledgement response.
 19. Theapparatus of claim 15, wherein the RTS comprises an address field toaddress the plurality of wireless communication devices.
 20. Theapparatus of claim 15, wherein the downlink transmission comprisessimultaneous transmission of a plurality of different downlink dataframes to respective ones of the plurality of wireless communicationdevices.
 21. The apparatus of claim 15 comprising a radio.
 22. Theapparatus of claim 15 comprising one or more antennas.
 23. A productcomprising one or more tangible computer-readable non-transitory storagemedia comprising computer-executable instructions operable to, whenexecuted by at least one computer processor, enable the at least onecomputer processor to implement at a wireless communication deviceoperations comprising: processing a Request to Send (RTS) from an AccessPoint (AP), the RTS addressed to a plurality of wireless communicationdevices comprising the wireless communication device, the RTS comprisinga duration value to reserve a wireless medium for a reserved timeperiod; transmitting a Clear to Send (CTS) response to the AP, the CTSresponse is based on scrambling information of the RTS; and subsequentto the CTS response, processing a downlink transmission from the AP, thedownlink transmission comprises a transmission from the AP addressed tothe plurality of wireless communication devices during the reserved timeperiod.
 24. The product of claim 23, wherein the operations comprisetransmitting the CTS response simultaneously with CTS responses fromother wireless communication devices of said plurality of wirelesscommunication devices.
 25. The product of claim 23, wherein theoperations comprise transmitting an acknowledgement response to the APsubsequent to the downlink transmission.
 26. The product of claim 25,wherein the reserved time period comprises at least a duration of thedownlink transmission and a duration of the acknowledgement response.27. The product of claim 23, wherein the RTS comprises an address fieldto address the plurality of wireless communication devices.
 28. Theproduct of claim 23, wherein the downlink transmission comprisessimultaneous transmission of a plurality of different downlink dataframes to respective ones of the plurality of wireless communicationdevices.